The Prairie Archives is a bookstore that has been around since 1973, and opened downtown in 1992. This store has a collection of over 250,000 books, many stemming from the history of Springfield and Abraham Lincoln. Aside from books, the Prairie Archives also sells comics, T-Shirts, and other collectibles. The Prairie Archives is a great one-stop-shop if you're looking to delve into the history of Springfield!
Find more information on their website: http://prairiearchives.com/